Controlled differential transmission mechanism



Dec. l2, 1950 E. F. NoRELlus 2,533,611

CONTROLLED DIFFERENTIAL TRANSMISSION MECHANISM Filed Dec. 28, 1946 4 Sheets-Sheet l N s. ,m

Dec. 12, 1950 E. F. NoRELlus CONTROLLED DIFFERENTIAL TRANSMISSION MECHANISM Filed Dec. 2a, 194e 4 sheets-smet 2 Dec. l2, 1950 E. F. NoRELlUs coNTRoLLED DIFFERENTIAL TRANSMISSION NEcHANIsN 4 Sheets-Sheet 3 Filed Dec. 28, 1946 mw mh, mw

n @w Nv NN 9%@ @Nw @MM/f Dec. l2, 1950 E. F. NoRELlus CONTROLLED DIFFERENTIAL TRANSMISSION MECHANISM 4 Sheets-Sheet 4 Filed Dec. 28. 1946 xv ww wN @MY mM, Nxs

/MMMA Patented Dec. 12, 1950 CONTBOLLED DIFFERENTIAL TRANSMS- SION MECHANSM Emil F. Noreiius, Springiield, lll., assignor to Allis-Chalmers Manufacturing Company, Miiwaukee, Wis., a corporation of Delaware Application December 28, 1946, Serial No. 719,032

(Cl. 'I4-710.5)

25 Claims. l

This invention relates, in general, to power transmitting mechanisms, and it is concerned more particularly with a drive mechanism for a pair of relatively rotatable shafts or the like, which is operable to transmit a common driving torque to said shafts and to differentiate the speeds at which the latter are driven by said torque.

The invention contemplates the provision of a mechanism for the stated purpose which utilizes certain basic features which are disclosed and claimed in my copending application Serial No, 642,357, filed on January 19, 1946, for Driving and Steering Mechanism for Motor Vehicles.

Power transmitting mechanisms of the general character outlined hereinbefore have been suggested. particularly for use in motor vehicles such as crawler tractors, which are steered by driving, that is, in which steering is effected by controlling the drive of ground engaging traction devices at opposite sides of the vehicle. According to such earlier suggestions a pair of relatively rotatable driven shafts are connected with each other by a differential mechanism, and driving power is applied to said differential mechanism in two ways, namely, ilrst. by means of a driving shaft which is geared to the spider of the differential mechanism, and second, by means of an auxiliary gearing which is connected in driving relation with the compensating gearing of the diii'erential mechanism and in driven relation with an auxiliary drive element, which may be driven to actuate the auxiliary gearing and thereput element of the auxiliary planetary gear train remains stationary while driving power is applied to the spider of the differential mechanism, and so that driving power may be applied to the auxiliary planetary gear train irrespective of whether the spider of the differential mechanism is rotating or locked against rotation. It is further desirable and the invention contemplates, to arrange the mechanism in such a manner that the auxiliary planetary gear train and the speed changing mechanism will function to lock the compensating gearing of the diiferential mechanism against compensating action upon locking of the power input element of the planetary gear train, but without restraining the locked compensating gearing against rotation as a whole, so that the driven shafts may be rotated in unison with each other as if they were rigidly connected together.

It is a further object of the invention to provide an improved power transmitting mechanism of the character outlined hereinbefore, in which by impress a. differential drive upon the driven shafts.

Generally. it is an object of the invention to provide an improved mechanism of the above stated character which is more satisfactory from an engineering and performance standpoint than those which have heretofore been suggested.

More specifically, it is an object of the invention to provide a power transmitting mechanism of -the above mentioned character in which a main diilerential, an auxiliary planetary gear train. and a planetary type speed changing mechanism are combined to form a compact assembly, the auxiliary planetary gear train and speed changing mechanism being mounted within a rotatable drum or the like. which also encloses the compensating gearing of the main dinerential and which serves as a spider for the planet pinions of the main differential.

For practical reasons it is generally desirable, Vand the invention contemplates. to arrange the mechanism in such a manner that the power inauxiliary driving power for rotating the driven shafts at diiferentiaispeeds may be appliedselectiveiy either to a component element of the auxiliary planetary gear train or to a component element oi' the planetary type speed changing mechanism so that. in a motor vehicle for instance, steering to one side may be effected by rotating thecomponent element of the auxiliary planetary gear train in a. predetermined direction. and so that steering to the other side may be effected by rotating the component element of the speed changing mechanism in said predetermined direction.

A further object of the invention is to provide an improved power transmitting mechanism of the hereinbefore outlined character in which the compensating gearing of the differential mechanism will be locked against differential action when the mentioned component element of the auxiliary gear train and the mentioned component element of the speed changing mechanism are restrained against rotation and in which the locked compensating gearing of the main differential may rotate as a. whole so that the driven or power output shafts may rotate in unison with each other either in a forward or a reverse direction as if they were rigidly connected together.

It is also an object of the present invention to provide an improved modied form of the mechanism disclosed in the mentioned earlier application to the end of simplifying the mechanism and rendering it more desirable from ah engineering and manufacturing standpoint.

These and other objects and advantages are attained by the present invention, various novel features of which will be apparent from the de scription herein and the accompanying drawings disclosing several embodiments of the invention, and will be more particularly pointed out in the accompanying claims.

In the drawings:

Fig. l is a'view, partly in section, of a drive mechanism for a motor vehicle, the view being taken in a horizontal direction.

Fig. 2 is a sectional view of a compound differential and steering unit incorporated in the mechanism shown in Fig. l.

Figs. 3 and 4 are further sectional views of the compound differential and steering unit, the view of Fig. 3 being taken on line III--III of Fig. 2, and the view of Fig. 4 being taken on line IV-IV of Fig. 2. y

Fig, 5 is a top view of part of the mechanism shown in Fig. 1 and of a hydraulic torque converter arranged in driving relation with the mechanism.

Fig. 6 is a schematic view of a modification of the compound differential and steering unit shown in Fig. 2.

Figs. 7, 8 and 9 are schematic views, respectively, of further modifications of the compound differential and steering unit shown in Fig. 2.

Referring to Fig. 1, the drive mechanism shown in this figure is intended, as stated, forincorporation in a motor`vehicle, and it comprises a main power transmitting gearing. Dart of which is shown in the left half of the figure, for transmitting propelling power to traction devices, not shown, at opposite sides of the vehicle, and an auxiliary power transmitting gearing, part of which is shown n the right half of the figure, for transmitting steering power to the traction devices.

Referring to the gearing which is shown in the left half of Fig. 1, and which constitutes an automotive type change speed transmission affording two forward speeds and one reverse speed, the input shaft of said transmission is indicated by the reference character I. A bevel gear 2 for applying driving power to the input shaft I through a hydraulic torque converter, as will be more fully discussed hereinbelow with reference to Fig. 5, is non-rotatably secured to the input shaft I at the right end of the latter. Mounted on the input shaft I, between bearings 3 and 4, are a low speed gear 6, a high speed gear 1 and a reverse speed gear 8, each `of the gears 6, 1 and 8 being supported on the input shaft for rotation relative thereto. A hydraulically operated clutch, generally indicated by the reference character 8, is operatively interposed between the input shaft I and the low speed gear 8. the clutch 9 being operable by application of fluid pressure thereto to connect the gear B with the shaft I for rotation of the gear 6 in unison with the shaft I, and to disconnect the gear 6 from the shaft I for rotation of the gear 8 relative to the shaft I upon release of said fluid pressure. Another hydraulically operated clutch, generally indicated by the reference character Il, is operatively interposed between the shaft I and the high speed gear 1, and between the shaft I and the reverse speed gear 8, the clutch II being operable by application of fluid pressure thereto to connect both gears 'I and 8 with the shaft I for rotation in unison with the latter, and to disconnect both gears 1 and 8 from the 4 shaft I for rotation relative thereto upon release of said fluid pressure.

A quill shaft I2 which constitutes the output shaft of the change speed transmission, is journaled in bearings I8 and I4 below the input shaft I, and carries a large diameter low speed gear I6, a small diameter high speed gear I1, and a large diameter reverse speed gear I8. The low speed gear I6 is splined to the quill shaft I2 and is axially fixed on the latter for constant mesh with the low speed gear 6. The high speed gear I1 and the reverse speed gear I8 are rotatably mounted on the quill shaft I2 in axially fixed positions by means of roller bearings I8 and 2l respectively, which permit each of these gears to rotate independently of the other relativeto the shaft I2, the gear I1 being arranged in constant mesh with the high speed gear 1. The reverse speed gear I8 is connected with the reverse speed gear 8 through an idler gear 22 which, for clarity, is shown in Fig. 1 above the gear 8, but which is actually arranged In constant mesh with the gears 8 and I8. A clutch collar 28 is splined on the quill shaft I2 and may be shifted axially in one direction into clutching engagement with the high speed gear I1, and in the opposite direction into clutching engagement with the reverse gear I8.

The hydraulic clutches 8 and II are controlled by a plunger 24 which is axially slidable within the shaft I and which has an internal passage in communication with a suitable source of fluid pressure, not shown. In the position in which the control plunger 24 is shown in Fig. l no pressure fluid can pass to either'of the clutches 8 and `II and the gears 6 and 1 are therefore declutched from the shaft I and the transmission is in neutral. In other words, Fig. 1 shows the control plunger 24 adjusted to a neutral position. In order to clutch the low speed gear 6 to the shaft I and thereby establish the low speed drive, the control plunger is moved from its neutral position towards the right in Fig. l, to a position in which pressure fluid is admitted through the plunger to the clutch 8. Normally, the clutch collar 23 is engaged with the high speed gear I1, and Vduring low speed drive the high speed gear I will therefore be rotated at a slower speed than the input shaft I, the clutch II being vented and therefore disengaged during low speed drive. In order to establish the high speed drive the control plunger 24 is adjusted from its neutral position towardsA the left in Fig. l to a position in which the clutch 8 is vented and pressure fluid is admitted through the plunger to the clutch II. The power flow is then from the shaft I through the clutch II, gears 1 and I1, and clutch collar 23 to the output shaft I2. During high speed drive the low speed gear 6 is declutched from the shaft I due to the venting of the clutch 8, and the low speed gear 6 will be driven at a higher speed than the input shaft I.

In order to establish the reverse speed drive, the clutch collar 23 is moved into clutching engagement with the reverse speed gear I8 while the control plunger 24 is in its neutral position, and thereafter the control plunger is moved t0 ilts high speed position so as to engage the clutch Ihe quill shaft I2 has an enlarged head 26 to which a drum 21 is secured coaxially with the quill shaft, as by a circumferential series of bolts 28 one of which is shown in Fig. 2. Another head 28 is similarly secured to the end :,ssaon of the drum 21 remote from the head 29, as by a circumferential series of bolts 3| one of which is shown in Fig. 2. The head 29 has a central hub portion which is rotatably mounted in a ball bearing 32, a stationary support for the ball bearing 32 being indicated at 33. 'I'he support 33 may be part of a large casing structure which has a suitable wall portion 34 for mounting the bearing 3 of the input shaft and the bearing I3 of the output shaft I2, and another wall portion 39 for mounting the bearing 4 of the input shaft and the bearing I4 of the output shaft. A stationary wall portion 31 to the left of the wall portion 39, for a purpose which will' be described hereinbelow. also preferably forms vpart of said casing structure.

Referring to Fig. 2, a pair of relatively rotatable differential half-shafts W and X which are aligned on the axis of the quill shaft l2 (see Fig. l), extend through the hubs 29 and 29, respectively, into the space within the drum 21. The two half-shafts W and X are differentially connected with each other within the drum 21 by a .dierential mechanism which comprises a pair of sun gears, generally designated by the reference characters 39 and 39, an annular planet carrier 4|, and a set of four conical planet pinions 42 which are journaled. respectively, on four radial trunnions 43 of the planet carrier 4|, as best shown in Fig. 3, and which mesh with the sun gears 39 and 39.

The sun gear 38 is made up in the form ot a composite structure which comprises a mounting hub 44; a disk piece 49 and an annular bevel gear Section 41. The mounting hub 44 is non-rotatably secured to the half-shaft W at the end of the latter adjacent to the half-shaft X, the halfshaft W having external splines 49 in engagement with internal splines of the hub 44. As best shown in the upper part of Fig. 2, a bolt 49 extends through the disk 49 and through an ear portion 45 of the hub 44, and a nut 9| is drawn up on the bolt 49 to rigidly secure the disk 49 to the hub 44. Referring to Fig. 4. it will be noted that three bolts 49 are equally spaced circumferentially of the hub 44, and the foregoing description with reference to the bolt 49 in Fig. 2, applies to all of the three bolts 49 shown in Fig. 4.

The disk piece 49 has a central hub which is rotatably supported on the head 29 by means of a rollexl bearing 92. At its periphery, the disk piece 49 has an axially extending rim portion 93, and an annular series of axially extending coupling teeth 94 are formed at the inside of the rim portion 93, as best shown in Fig. 3.

The bevel gear section 41 of the sun gear 39, which meshes with the conical planet pinions 42, hasA an annular skirt portion which is seated axially against an inner shoulder on the rim portion 93 of the disk piece 49. The bevel gear section 41 is circumferentially interlocked with the disk piece 49 by means o1' a circumferential series of external coupling teeth 99 which are formed on the skirt portion of the bevel gear section 41 and which extend axially into the spaces between the coupling teeth 94|, as best shown in Fig. 3.

The sun gear 39 is an exact duplicate of the sun gear 39, and the same reference characters which have been applied in Fig. 2 to the various parts of the sun gear 39, have been applied in the same figure to the corresponding parts of the sun gear 39. The disk piece 49 of the sun gear 39 is rotatably supported on the head 29 of the drum 21 by means of a roller bearing 91, and the mounting hub 44 of the sun gear 39 is non-rm tatably connected with the half-shaft X by means ci' external splines 99 of the latter matching iriternal splines of the surrounding mounting hub 4.

The radial trunnions 49 of the annular planet carrier 4| are interlocked with the drum 21 by means of annular cover plates 99. as best shown in Fig. 3. The axes of the trunnions 43 coincide with the axes of four relatively large radial holes 9| in the drum 21 midway between the opposite ends of the latter. The diameters of the holes 9| are slightly larger than the maximum diameters of the conical pinions 42 so that the latter can be slipped over the trunnions 43 after the one-piece annular planet carrier 4| has been moved into the drum. The plates 59 are then slipped over the trunnions 43 into the positions in which they are shown in Fig. 3, and in which positions they are secured to the drum 21 by cap screws 92, each plate being retained by four cap screws as shown inv Fig. 1. To provide proper seats for the cover plates, flats are milled on the outside of the drum, as shown in Fig. 3, and each cover plate has a cylindrical hub which snugly fits into the respective hole 9|.

From the foregoing description it will be seen that torque applied to the output shaft I2 of the change speed transmission will be transmitted through the head 29, drum 21 and cover plates 99 to the trunnions 43 of the planet carrier 4|. From the planet carrier 4| the torque is transmitted to the half-shafts W and X through the corneal planet pinions 42 and sun gears 39 and 39 in conformity with the well-known principles of an ordinary bevel gear differential, the pinions 42 and sun gears 39, 39 corresponding to the compensating gearing of such a diilerential.

In addition to the compensating gearing 39, 39 and 42, the drum 21 encloses an epicyclic gear system which forms part of the hereinbefore mentioned auxiliary gearing for impressing a differential drive upon the shafts W and X. As shown in the left hand lower half of Fig. 2, the mounting hub 44 of the sun gear 39 has an ear portion 93 in axially spaced relation to the radial web portion of the disk piece 49. and a pin 94 is non-rotatably mounted in aligned holes of the disk piece 49 and of the ear portion 93. The pin 94.has a threaded end portion on which a nut 99 is drawn up against the ear portion 93. Rotatably mounted on the pin 94 by means of a roller bearing 91 is a spur gear planet pinion 99.

Referring to Fig. 4, it will be noted that three pins 94 are equally spaced circumferentially of the hub 44, and that each of the pins 94 carries a spur gear planet pinion 99, the same as described hereinbefore with reference 'to Fig. 2. As indicated in Fig. 4, webs 99 are arranged in the spaces between the planet pinions 99, and these webs connect the ear portions 49 with the ear portions 93 of the mounting hub 44.

Each of the planet pinions 93 meshes with an auxiliary sun gear 1| which is mounted coaxially with the shaft W on a long sleeve 12, the sun gear 1| being splined on and thus non-rotatably secured to the sleeve 12 at the end of the latter adjacent to the mounting hub 44. Referring to Fig. l, it will be seen that the sleeve 12 extends through the quill shaft I2 and has a flange at its outer end which is rigidly secured, as by bolts 13, to the mentioned stationary wall portion 31. The inside diameter of the sleeve 12 is somewhat larger than the outside diameter of the shaft W, and the outside diameter of the sleeve 12 is some what smaller than the inside diameter of the quill shaft I2, so that both the shaft W and the quill shaft i2 may freely rotate relative to the stationary sleeve 12. A bushing 14 is interposed between the sleeve 12 and the hub ofthe disk piece It in order l to center the auxiliary sun gear 1| relative to the sun gear 3l. y

Another set of three auxiliary spur gear planet pinions 16 are mounted on the sun gear It of the main dierential, the mounting of the planet pinions 16 corresponding to the mounting of the planet pinions il on the sun gear 3l, and the foregoing description of the mounting of the planet pinions 68 similarly applies to the mounting of the planet pinions 1l.

The three spur gear planet pinions 8l and the three spur gear planet pinions 1t are enveloped, respectively, by counter gear elements, that is by ring sections 11 and 18 of a sleeve gear which is generally indicated by the reference character Il. 'I'he sleeve gear l0 is arranged within the drum 21 concentrically with the shafts W and X and it is rotatable relative to the annular planet carrier 4| and also relative to the sun gears 3l, Il about the common axis of the shafts W and X. The two ring sections 11 and 1l of the sleeve gear Il are rigidly connected together, inside of the annular planet carrier 4i, by a circumferential series of bolts 19, and axial movement of the sleeve gear Il relative to the planet carrier Il is limited by wear rings 8| and l2 on the ring sections 11 and 18, respectively.

The ring section 11 of the sleeve gear It has a circumferential series of internal gear teeth 8l. as best shown in Fig. 4, and the spur gear planet pinions il are in mesh with said circumferential series of internal gear teeth 8l. The ring section 1l oi' the sleeve gear 80 has a similar circumferential series of internal gear teeth 84 (Fig. 2), the pitch diameter and the number of the gear teeth Il being the same as the pitch diameter and the number of the gear teeth I3. The spur gear planet pinions 1i are in mesh with the circumferential series of internal teeth Il, the relative arrangement of the planet pinions 16 and ring sections 1s corresponding to the relative arrangement of the planet pinions and ring section 11 which is shown in Fig. 4. The set of spur gear planet pinions 68 affords a threepoint support for the ring section 11, and the set of spur gear planet pinions 18 affords a threepoint support for the ring section 18. The supports afforded by the planet pinions 68 and 18 iioatlngly maintain the sleeve gear 80 asa whole in rotatable relation to the sun gears Il and 39 sleeve which is formed on the disk piece I6 of the sun gear 39, and through the hub of the head 29, a bushing 88 being interposed between the sleeve l1 and the surrounding hub sleeve of the outside diameter of the sleeve l1 is somewhat smaller than the inside diameter of the hub sleeve on the head 2l, and the sleeve I1 is thus rotatively loose relative to the shaft X, sun gear II. and drum 21.

Referring to Fig. 1, the outer end of the sleeve 81. is rotatably mounted on a stationary support l! by means of a ball bearing tl, the support ll preferably forming another wall portion of the mentioned casing structure which includes the wall portions 33, 34, It and I1. Mounted on the portion of the sleeve l1 which extends between the ball bearings I2 and Il is a gear wheel I2 which has two peripheral gear sections I3 and 84, the hub of the gear wheel I2 being splined on the sleeve l1 so as to lock the gear wheel I2 and sleeve 81 together for rotation as a unit about the axis of the shaft X.

The portion of the sleeve l1 which extends between the gear wheel l2 and the bearing li is surrounded by a stationary brake drum Il which is secured to the support Il. as by cap screws I1. A' suitable brake mechanism including a stack of brake disks 88 is arranged inside of the drum tt and connected with the sleeve I1 for the purpose of releasably securing the sleeve l1 against rotation. The brake mechanism may be of any conventional type, and for purposes of explanation it may be assumed that the drum Il encloses, in addition to the stack of disks Il, a hydraulically operable mechanism which functions in response to admission of iiuid pressure thereto to axially compress the stack of disks Il so that braking force will be applied to the sleeve 81, and which mechanism functions in response to release of said fluid pressure, to relieveV the stack of disks of axial compression so that the sleeve l1 will be released for rotation relative to the drum Il.

An auxiliary drive shaft ll is rotatably mounted in axial alignment with 'the input shaft I of the the disk 46 to rotatably support the sleeve 81 change speed transmission, as shown in Fig. l. antifriction bearings for rotatably supporting the shaft ss being mounted in supports iti, |l2 and in which, like the supports 33, 34, Il.' 31 and l! may be wall portions of the mentioned casing structure. In the space between the supports Il! and ID3 a driving gear |04 in constant mesh with the gear section s3 of the gear l2 is mountedon the shaft I! in rotatively loose relation'v thereto, and a hydraulic clutch, generally indicated by the reference character |08, is operatively interposed between the shaft ,l and the gear i, the clutch |08 being operable upon admission of fluid pressure thereto, to clutch the gear IM to the shaft 89 and to declutch'it therefrom upon release of said fluid pressureg.

Also rotatably mounted on the shaft 9s between the supports |02 and I" is a reverse driving gear |01, and another hydraulic clutch, generally indicated by the reference character I, is opera tively interposed between the shaft Il and the reverse gear |01, the clutch |08 being operable upon admission of fluid pressure thereto, to clutch the gear |91 to the shaft It and to declutch it therefrom upon release of said fluid pressure. The reverse driving gear is drivingly connected with the gear section Il of the gear wheel I2 by an idler gear |09 which is shown in Fig. i, for clarity, above the gear |01 but which lis actually mounted in such a position so as to be in constant mesh with the gear |01 and with the gear section Il of the gear wheel Il.

The hydraulic clutches l and Ill are controlled in a suitable manner, as by means ot a with a tubular shaft II4.

assacii control plunger ||I which, like the control plunger 24 of the change speed transmission, may be adjusted to a neutral position and to two drive establishing lpositions, the arrangement being such that upon adjustment ofthe control plunger to its neutral position both gears |04 and |81 are declutched from the auxiliary drive shaft I8, and that a forward driving connection between the shaft 99 and the sleeve 81 will be established upon adjustment of the control plunger I I I to one of its drive establishing positions, and that a reverse driving connection between the shaft 88 and the sleeve 81 will be established upon adjustment of the control plunger III to the other of its drive establishing positions.

The control mechanism for the clutches |06 and |88 is preferably interrelated with the control mechanism for the brake mechanism within the brake drum 96 in such a manner that when the control plunger III is in its neutral position the brake mechanism is effective to apply a braking force to the sleeve 81, and that such braking force is automatically released whenever the control plunger I I I is moved from its neutral position to either of its drive-establishing postions, that is. the sleeve 81 will be released for rotation preparatory to establishment of the forward driving connection through the clutch I 06, and also preparatory to establishment of the reverse driving connection through the clutch |08.

Integrally formed with the auxiliary drive shaft 99 at the end of the latter next to the input shaft I of the change speed transmission, is a bevel gear ||2 for application of driving power to the shaft 99, as will be described hereinbelow.

Referring to Fig. 5, the bevel gear 2 of the input shaft I of the change speed transmission meshes with a bevel gear I I3 which is rigidly connected The shaft ||4 forms the tail shaft of a hydraulic torque converter, which is generally indicated by the reference character ||6, and which comprises a housing A ||1. an input shaft I I8, a pump rotor ||9 secured to the input shaft ||8, two sets of reaction blades |2| secured' to the housing |I1, and a turbine wheel |22 secured to the tubular tail shaft |I4. As to its general construction and mode of operation, the torque converter II 6 conforms with well-known principles, and a further description in this connection is believed unnecessary. It should be noted, however, that the input shaft I |8 has an axial extension |23 which is directly coupled to the input shaft II8 for rotation in unison therewith, the extension |23 being freely rotatable within the tubular tail shaft ||4 and projecting rearwardly beyond the bevel gear ||3 and past the bevel gear I I2 of the auxiliary drive shaft 99.- A companion bevel gear |24 for the bevel gear ||2 is splined on the rear end of the extension shaft |23 for transmitting driving power from the latter to the auxiliary drive shaft 99. The bevel gear |24 has an axially extended hub sleeve which is rotatably mounted in a bearing |26, and a power take-oil shaft |21 for general utility purposes has a splined connection with the hub sleeve of the bevel gear |24.

All of the mechanism shown in Figs. l to 5 inclusive is intended. as has been mentioned hereinbefore, for installation in a motor vehicle, not shown, and provisions will have to be made for connecting the vehicle motor in driving relation with the input shaft I8 of the hydraulic torque converter ||6, and for connecting traction devices atl opposite sides of the vehicle in driven relation with vthe half-shafts W and X, re-

10 spectively. Such provisions may be made in conventional manner -and are therefore believed to require no further explanation. It should be noted, however, that due to the incorporation of the hydraulic clutches 9 and rII in the change speed transmission, which have been described hereinbefore in connection with Fig. 1, the driving shaft of the vehicle engine may be coupled directly to the input shaft I|8 of the torque converter. that is, without the interposition of the usual master clutch between the vehicle engine and the input shaft of the torque converter.

The mode of operation of the change speed transmission, and the transmission of torque from the transmission output shaft I2 to the halfshafts W and X through the compensating gearing comprising the conical planet pinions 42 and the sun gears 38 and 39 has already been explained hereinbefore. The arrow |28 in Fig. 2 indicates the direction in which the output shaft I2 -may be rotated for forward propulsion of the vehicle upon establishment of the low speed drive through the clutch 9, and upon establishment of the high speed drive through the clutch II, it being understood that traction devices at opposite sides of the vehicle are connected with the shafts W and X through iinal drive gearing, not shown, which reverses the rotation of the traction devices relative to the respective shafts W and X.

Let it now be assumed that the gears |04 and |01 of the auxiliary gearing are declutched from the auxiliary drive shaft 99 by the clutches |06 and |08, and that the converter input shaft II8 and the converter tail shaft I! 4 `are running in order to rotate the output shaft I2 of the change speed transmission in the direction of arrow |28 in Fig. 2. Rotation of the extension shaft |23 incidental 'rotation of the input shaft 8 will be transmitted through the bevel gears |24 and I I2 to the auxiliary drive shaft 99, but since both gears |04 and |01 are declutched from said shaft, no rotation will be transmitted to the gear wheel 92 and the sleeve 81 which carries the auxiliary sun gear 88. In actual practice, the sleeve 01 is preferably locked against rotation by the bra-ke Amechanism 96, 98 as long as both gears |04 and |01 are declutched from the shaft 99.

vUnder thev assumed conditions rotation of the transmission output shaft I2 in the direction of arrow |28 in Fig. 2, will be effective to also rotate the shafts W and X in the direction of arrow |28, the main sun gears 38 and 39 rotating'in unison with the planet carrier 4|, that is, without rotation relative to each other. Such unitary rotation of the sun gears 38 and 39 imparts an orbital movement to the spur gear planet pinions 68 and 16, which are in mesh, respectively, with the auxiliary sun gears 1| and 86. In the embodiment of the invention as shown in Fig. 1, the auxiliary sun gear 1| is permanently xed against rotation, and since lthe auxiliary sun gear 86 is also xed against rotation by application of a braking force to the sleeve 81, as assumed at present. it follows that the spur gear planet pinions 68 and 16 will rotate about the axes of their respective supporting pins 64. while the sun gears 38 and 39 are rotated inthe direction of arrow |28.

The pitch diameter and the number of teeth Y `or manet pinions n and 1s has infernal teeth u and the shafts W and x rotate, while the auxiliary sun gear 86 is locked against rotat on.

The assembly comprising the planet carrier 4|, the bevel pinions 42, the sun gears 88 and 39 and the shafts W and X is rotatable as a unit, practically without restraint by the auxiliary gearing within the drum 21, when both auxiliary sun gears 1| and 86 are locked against rotation. It will be noted, however, that relative rotation of the shafts W and X about their common axis is made impossible by the locking of the auxiliary sun gear 86. If the shaft X, for instance. should tend to overrun the shaft W, the set of spur gear planet pinions 16 would tend to increase the speed of the sleeve gear 88, but the speed of the sleeve gear 88 can obviously not be increased without at the same time increasing the speed of the shaft W throughthe set of spur gear planet pinions 68. The inability of the shafts W and X to rotate relative to each other while the sun gear 86 is locked against rotation, precludes differential action of the main differential 38, 38, 42 or in other words, the main differential is locked by locking of the sun gear 86.

Considering now the application of driving torque to the auxiliary sun gear 86 through the gear mechanism which is interposed between the sleeve 81 and the auxiliary drive shaft 99, as shown in Fig. 1, the following is to be noted'.

Engagement of the hydraulic clutch |86 couples the gear |84 to the `auxiliary'drive shaft 88, as has been explained hereinbefore, and for purposes of explanation it may rst be assumed that such engagement of the clutch "|88 is effected while the input shaft 8 and the shaft extension |23 of the torque converter ||6 are running but the change speed transmission is in neutral, and consequently no driving torque is transmitted to the output shaft I2 and to the drum 21. Rotation of the shaft extension |23 is transmitted to the auxiliary drive shaft 99 through the bevel gears |24 and ||2, and before the clutch |86 is engaged the brake mechanism 86, 88 is released, as explained hereinbefore. Upon engagement of the clutch |86, the sleeve 81 and the sun gear 88 will then be rotated in the direction of arrow |29 in Fig. 2. The rotary torque acting on the auxiliary sun gear 86 tends to rotate the spur gear planet pinions 16 about their supporting pins 64, but these pinions mesh with the sleeve gear 88, and the torque of the sun gear 86 is therefore transmitted through the pinions 16 in reverse direction to the sleeve gear 88 and tends to turn said sleeve gear in the direction of arrow |3| in Fig. 2. The sleeve gear 88, in turn, meshes with the spur gear planet pinions 68, and the tendencyof the sleeve gear 88 to rotate in the direction of arrow |8| causes a tendency of the spur gear planet pinions 68 to rotate about the axes of their supporting pins 84. However, since the planet pinions I68 are in mesh with the auxiliary sun gear 1| which, as

12 upon the mounting pins 84o! the planet pinions 68, which are secured to the sun gear 88, and the rotary reaction of the locked sun gear y1| upon the planet pinions 88 further causes an orbital reaction, in the direction of arrow |28, upon the mounting pins 84 of the planet pinions 18 which are secured to the sun gear88, and as a further result the bevel pinions 42 which are in mesh with the sun gears 38 and 39 become,

subjected to a rotary torque which tends to turn the-pinions 42 about the axes of their respective mounting trunions 43. From these considerations it will be apparent that the sun gear 88 and the shaft W which is non-rotatably connected with said sun gear will be rotated in the direction of arrow ISI, and that the su`n gear 88 and the shaft X which is non-rotatably connected therewith will be rotated in thedirection of arrow |29 when the sleeve 81 and the s un gear 86 are rotated in the direction of arrow |29. In other words, application of driving power to the auxiliary gearing by engagement of the clutch |86 impresses a differential drive upon the shafts W and X, and under the assumed condition that no torque isapplied to the drum 21V by the output shaft I2 of the change speed transmission, the speeds at which-the shafts W and X are driven will be the same, the shaft W turning in the direction of arrow |3| at the same speed as that at which the shaft X turns in the direction of arrow |29.

Designating the rotary speed of the sleeve 81 and sun gear 86. that is their number of revolutions per minute. as N, and further designating the rotary speed of the shaft X, that is its number of revolutions per minute, as n, it can be shown that the gear ratio between the sleeve 81 v wherein d represents the identical tooth numbers at opposite ends of the sleeve gear 88, that is the number of teeth 83 which is identical with the number of teeth 84, and wherein s represents the identical tooth numbers of the auxiliary sun gears 1| and 86, that is, the number of gear teeth on one of these gears which is identical with the number of gear teeth on the other. The first plus sign in the above expression indicates that the direction oi' rotation of. the shaft X is the 1 same as that of the sleeve 81 and sun gear 86.

stated, is locked against rotation, the planet pinions 68 cannot rotate freely on their supporting pins 64. 'I'he rotary reaction of the locked sun gear 1| upon the planet pinions 68 causes an orbital reaction, in the direction 0f arrow III,

The arrow |29 in Fig. 2 indicates the direction in which the sleeve 81 and the sun gear 86v are rotated upon engagement of the clutch |88, as explained hereinbefore. From Fig. 1 it will be apparent that engagement of the clutch |88 will cause transmission of driving power from the shaft 99 to the sleeve 81 and sun gear 86 in such a'manner that the direction in which the sleeve 81 and the sun gear 86 rotate will be opposite to that indicated by the arrow |29. Such opposite rotation of the sleeve and sun gear will again impress a differential drive upon the shafts W and X, as will be readily understood in view of the foregoing explanations, but the directions in which the shafts rotate will be opposite to those in which they are rotated upon engagement of the clutch |86; that is, the shaft W will be rotated in the direction of arrow |28 and the shaft X will be rotated in the direction of arrow |8|.

The hydraulic clutches 8 and Il of the change V13 i speed transmission are operable independen of the hydraulic clutches |38 and |88 of the auxiliary gearing. andalso independently of the brake mechanism 88, 88. Let it now be assumed that the low speed drive is established by ensagement of the clutch 8 and that while the output shaft |2 is rotating in the direction of arrow |23, the clutch |88 is engaged after release of the brake mechanism 83, 83. In that case a differential drive will be super-imposed upon the drive which is transmitted to the shafts W and X through the main diiferential 38, 38 and 42. The mechanism as a whole now functions to rotate the shaft W in the direction of arrow |28 but at a lower speed than the transmission output shaft I2, and to also rotate the shaft X in the direction of arrow |28 but at higher speed than the transmission output shaft |2, the speed decrease of the shaft W from the speed of the output shaft I2 being equal to the speed increase oi' the shaft X over the speed of the output shaft I2.

If, instead of the clutch |88, the clutch |88 is engaged while the low speed drive is established and the output, shaft I2 is rotating inthe direction o f arrow |28, the shafts W and X will again be driven at diiIerent speeds in the direction of arrow |28, but in this case the shaft X will rotate at a lower speed, and the shaft W will rotate at a proportionally higher speed, than the output shaft I2.

The foregoing explanations as to the functioning of the auxiliary gearing to superirnpose a vdifferential drive upon the main drive, that is,

upon the drive which is transmitted from the output shaft I2 to the shafts W and X through the differential 38, 38 and 42, while the change speed transmission is in low gear, similarly apply for operation of the change speed transmission in high gear and reverse gear. It should be noted, however, that the speed which is subtracted from the speed of the shaft W and which is added to the speed of the shaft X upon engagement of the clutch |88 is the same irrespective of whether the output shaft I2 lof the transmission is driven at a relatively low speed through the low speed gear train 8, |8 or through the high speed gear train 1, I1. 'I'his is so because the drive for the auxiliary gearing is derived directly from the input shaft of the torque converter rather than from the output shaftof the change speed transmission.

The foregoing considerations with respect to differential rotation of the shafts W and X asseoir lary drive shaft 88 is derived directly from the input shaft H8 through thefextension shaft |23 and the bevel gears ||2 and |24, as has been explaincd hereinbefore.

'Ihe advantages to be derived from the mec anism shown in Figs. 1 to 5, are particularly desirable in an automotive vehicle. In ythis consimilarly apply when the transmission of auxiliary driving power to the sleeve 81 is effected through the clutch |88, rather than, as assumed hereinbefore, through the clutch |88.

The torque converter ||8 operates to transmit power from the input shaft |I8 to the tail shaft I|4 in such a manner that the speed of the tail shaft will automatically adjust itself to prevailing load conditions, that is, under certain conditions the speed ofthe tail shaft I4 may fall considerably below the speed of the input shaft II8. Upon such deceleration of the tail shaft |I4 the speed at which the shafts W and X are driven through the ychange speed transmssion will nection reference may be had to the store-inentioned earlier application and tothe discussion therein of certain basic considerations regarding the construction and operation of motor vehicles which are steered by driving. Said considerations include the provision of a speed reducc ing planetary gearing which relieves the steering power transmitting mechanism from undesirably high torque loads and thereby makes-it possible to construct said mechanism substantially lighter than the propelling power transmitting mechanism; further, the provision of predetermined radii of turning of the vehicle; the elimination of friction losses during turning; positive control of the traction devices at all times; and several ancillary matters. The mechanism disclosed herein incorporates the basic operating characteristics by means of which all of these matters may be taken care of in a practical and entirely satisfactory manner.

For motor vehicle use it may be required or desirable to incorporate a service brake in the mechanism shown in Fig. l, and the drum 21 may readily be utilized for that purpose. A brake band, generally indicated by the reference character |32 in Fig. 1, is arranged around the drum 21, and a suitable mechanism, not shown, may be provided for tightening the brake band upon and releasing it from the drum, friction linings for engagement with the cylindrical outer surface portions of the drum at opposite sides of the cover plates 58 being indicated at |33. c

The principal operating characteristics of the mechanism shown in Figs. 1 to 5 may be incorporated in a variety of modified constructions some of which are shown schematically in Figs. 6` to 9, inclusive.

v In Fig. 6, shafts W and X are connected with each other by a diiIerential mechanism which, like the diil'erential mechanism shown in Fig. 2, 'comprises annular planet carrier 4|, bevel pinions 42 and sun gears 38 and 38. In conformity with the mechanism shown in Fig. 2, the mechanism shown in Fig. 6 further comprises auxiliary sun gears 1I and 86 mounted on sleeves 12 and 81, respectively; two sets of spur gear planet pinions 88 and 16 mounted, respectively, on the sun gears 38 and 38, and a sleeve gear 88. As distinguished from the planet pinions 88 in Fig. 2, the planet pinions 88 in Fig. 6 each have a near section |34 at the outer side of the sun gear 38and a gear section |38 at the inner side of the sun gear 38. Similarly, the planet pinions 16 in Fig. 6 have outer and inner gear sections |34 and |38 corresponding to the gear sections 34 and |38 of the planet pinions 88, and the outer gear sections |34 of the planet pinions 88 and 16 meshwith the sun gears 1| and 88, respectively. y As shown in Fig. 6 the sleeve gear' 88 has external gear teeth` and 84 in mesh, respectively, with the inner gear sections |38 of the planet pinions 88 and 18, and in this respect the sleeve gear 88 in Fig. 6 is distinguished fromv the sleeve gear 88 in Fig. 2 where the gear teeth 83 and 84 are formed internally of the sleeve gear 88. The gearing shown in Fig. 8 is enaumen l5 -closed in a rotatable stantial conformity with the showing in Fig. 2, a bevel ring |44 on the drum 21 being in mesh with a driving pinion |48. The explanation: hereinabove with respect to the mode of operation of the mechanism shown in Fig. 2 analo-= gously apply to the mechanism shown in Fig. 6.

In Fig. 7, shafts W andv X are connected with each other by a diiferential mechanism comprising a spider structure 21, conical planet pinions 42, and sun gears 88 and 88. Auxiliary gearing for impressing a dlerential drive upon the shafts W and X comprises two auxiliary sun gears 1| andv 88: two sets of planet pinions 8 8 and 18 which are mounted, respectively. on gear wheels |81 and |88; mating gears |88 and |4| for the gear wheels |81 and |88, respectively; and a, sleeve gear 88. The auxiliarysun gears 1| and 88 in Fig. 7 are aligned and supported on a stationary shaft |42 which is mounted in parallel relation to and spaced transversely from the common axis of the shafts W and X, supporting sleeves 12 and 81 for the sun gears 1| and 88, respectively, .corresponding to the supporting sleeves 12 and 81 in Fig. 2. The mounting gears 81 and |88 for the planet pinions 88 and 18 are mounted coaxially with and in rotatable relation to the shaft |42 and in rotatable relation to the sun gears 1| and 88. The mating gear |88 for the supporting gear |81 is mounted coaxially with and is non-rotatably secured to the shaft W, and the mating gear |4| for the gear |88 is mounted coaxially with and non-rotatably secured to the shaft X. A bevel pinion |48 for transmitting main driving power to the bevel gear differential 88, 88, 42 meshes with a bevel ring gear |44 secured to the spider structure 21. The mode of operation of the mechanism shown in Fig. 7 is similar to the mode Aof operation of the mechanism shown in Fig. 2, which will be readily apparent from the explanations hereinabove with reference to the mechanism shown in Figs. 1 to 5.

'In Fig. 8 shafts W and X are differentially l connected with each other in the same manner as shown in Fig. 7. Mounted coaxially with and non-rotatably secured to the shaft W is a bevel gear |48 which meshes with a bevel pinion |41 drum structure 21 in subone direction will cause rotation of the other gear |82 in the opposite direction. The mode of operation of the mechanism shown in Fig. 8l is similar to the mode of operation of the mechanism shown in Fig. 2, which will be apparent from the explanations hereinabove with reference to Figs. 1 to 5.

v f Fig. 9 illustrates an arrangement for'applying driving power alternatively to the auxiliary sun on a shaft |48, the latter being mounted for rotation on an axis extending at right angles to the common axis of the shafts W and X. The shaft |48 hasa head on which spur gear planet pinlons 88 are mounted for rotation about axes extending parallel to the axis of the shaft |48.

The planet pinions 88 are enveloped by an internally toothed ring section |48 of a gear |5| which is mounted in axial augment with the shaft |48 for rotation relative to the latter. An auxiliary sun gear 1| in mesh with the planet pinions 88 is mounted on a shaft 12 which, although it may be solid rather than tubular, corresponds to the shaft 12 in Fig. 2. The shaft X in Fig. 8 is connected with a gear system which is an exact duplicate of the gear system which is connected with the shaft W, and the various identical elements of the two-gear systems are designated by the same reference characters, except for the planet pinions, sun gear, and sun gear supporting shaft, which are designated by the reference characters 18, 88 and 81 in conformity with the reference characters in Fig. 2. Each of the gears |5| in Fig. 8 has a circumferential series of external teeth |82, and the two -gears are intermeshed by means of these external teeth so that rotation of one gear |82 in gear 88 and to the auxiliary sun gear 1| of the mechanism shown in Fig. 2. The gearing within the drum 21, as shown in Fig. 9, is identical with the gearing shown in Fig. 2, as will be readily recognized from a comparison of the two figures. Non-rotatably secured to the supporting sleeve 81 of the auxiliary sun gear 88 in Fig. 9, is a gear |88. and a similar gear |84 is non-rotatably secured to the supporting sleeve 12 of the sun gear 1|. The gears |58 and |54 mesh withlgears |88 -and |81, respectively, which are aligned on an auxiliary driving shaft 88. each gear |58 and |81 being mounted on the shaft 88 for rotation relative thereto and for rotation relative to the other. operatively interposed between the shaft 88 and the gear |58 is a disk clutch |88, and a similar disk clutch |58 is operatively interposed between the shaft 89 and the gear |81, Integrally formed with the gear |58 isa brake drum which is enveloped by a brake band 8|, and the gear |81 has a similar brake drum which is enveloped by a brake band |82.

'I'he shaft 88'in Fig. 9 carries a bevel gear |2 for the application of driving power thereto through a companion bevel gear |24 in substa tial conformity with the showing in Fig. 5.

A thrust collar |88 for engaging and releasing the clutch |58 is shiftable axially of theshaft 88 and is engaged by the upper end of a rock arm |84 which is fulcrumed intermediate its ends on a stationary bracket |88. Another thrust collar |81 and rock arm |88 corresponding to the thrust collar |88 and rock arm |84 provide for engagement and release of the clutch |88, the rock arm |88 being fulcrumed intermediate its ends on a stationary bracket |88. A control shaft |1| is mounted for rocking movement about its axis in parallel relation to the drive shaft 88 and carries two spiraily grooved cylinders |12 and |18, the spiral grooves of the cylinders being pitched so as to lead in the same direction. The lower'ends of the rock arms |84 and |88 engage the spiral grooves of the cylinders |12 and |18, respectively, so that the rock arms will be swung about their fulcrum centers at |88 and |88, respectively, by rocking movement of the control shaft |1| about its axis.

The control shaft |1| further carries two disks |14 and |18 each of which has an axially extending lug at its circumference, the disks being nonrotatably secured to the shaft 1| and the lugs being offset relative to each other circumferentially of the shaft. The purpose of the disks and lugs thereon is to tighten and loosen the brake bands |8| and |82 upon rocking of the control shaft, and two push rods |11 and |18 are provided for that purpose, the rod |11 extending of' clips connected. re-

rod. and at its upper end the coil spring bears against one of the clips of the brake band 17 |6I. The other clip of the brake band I6I is engaged by a head of the rod |11, and the coil spring |19 is properly preloaded so as to tighten the brakeband I6I and thereby lock the gear |56 against rotation. At its lower end the push rod |11 has an arm for engagement with the lug of the disk |14.

Another coil spring I8I is placed around the push rod |18, and the foregoing explanations with respect to the rod |11 and spring |19 similarly apply to the rod |18 and coil spring-[8L the coil spring I8I being effective to tighten the brake band |62 and thereby lock the gear |51 against rotation.

A lever I 82 is secured to the control shaft |1I, and may be swung either in the direction of arrow |10 or in the direction of arrow |80, in order to rock the shaft I1I about its axis when the lever |82 is swung in the direction cf arrow I 10 the lower end of the push rod |11 is engaged by the lug on the disk |14, and the arrangement is such that the movement transmitted to the rod |11 by rotation of the disk |14 in the direction of arrow |10 will push the rod |11 upwardly and thereby release the brake band I6I. ,The other brake band |62 will noi'be releasedby movement l of the disk |16 in the direction of arrow |10,"the

lug on the disk |16 being suitably arranged so that it will move away from the lower end of the rod |18 when the lever |82 is moved in the direction of arrow |10. On the other hand, when the lever |82 is swung in the direction of arrow |80, the brake |62 will be released by rotation of the disk |16, while the brake I6| remains lengaged, the lug on the disk |14 moving away from the lower end of the rod |11.

In the position of the parts as shown in Fig. 9, both clutches |58 and |59 are disengaged so that the shaft 99 may rotate freely while both gears |56 and |51 are locked against rotation by the brakes |6| and |62. When the lever I 82 is swung in the direction of arrow |10 and the brake I6I is thereby released, as explained hereinbefore, the clutch |58 will be engaged, but the clutch |59 will remain disengaged, the leads of the spiral grooves in the cylinders |12 and |13 being properly arranged so that both thrust collars |63 and |61 will be moved to the left in Fig. 9 when the lever |82 is moved in the direction of arrow |10. 0n

the other hand, when the lever |82 is swung in the direction of arrow |80 and the brake |62 is thereby released while the brake IGI remains engaged, the clutch |59 will be engaged while the clutch |58 remains disengaged, both thrust collars |63 and |61 moving to the right in Fig. 9, when the lever |82 is moved in the direction of arrow |80.

The arrow |29 in Fig. 9 indicates the direction in which the sleeve 81 and the sun gear 86 will be rotated when the brake I6I is released and the clutch |58 is engaged by movement of the lever |82 in the direction of arrow |10. The sun gear 1| will be locked against rotation while the sun gear 86 rotates in the direction of arrow |29 in Fig. 9 because the sleeve 12 of the sun gear 1| is connected through the gear |54 with the gear |51 and the latter gear remains locked by the brake |62 when the lever |82 is moved in the direction of arrow |18. As a result of the rotation of the sun gear 86 in the direction of arrow |29 while the sun gear 1I is locked, a differential drive is impressed upon the shafts W and X, as has been explained hereinbefore in connection with the mechanism shown in Figs. 1 to 5.

The arrow |29 in Fig. 9 also indicates the direction in which the sleevey 12 and the sun gear 1I will be rotated whencthe brake I 62 is released and the clutch |59 is engaged by movement of the lever |82 in the direction of arrow |80 in Fig. 9. Since the gear |56 remains locked by the brake I6I when the clutch |59 is engaged, the sun gear 86 will be locked against rotation while the sun gear 1| is rotated in the direction of arrow |29. As a result, a differential drive will again be impressed upon the shafts W and X, but the directions in which torque is applied to the shafts W and X by the auxiliary power derived from the shaft 99 in Fig. 9 will now be reversed as compared with the directions in which such torque is applied to the shafts W and X in the first case, that is, when the sun gear 86 is rotated in the direction of arrow |29 while the sun gear 1I is locked against rotation.

As pointed out hereinbefore, the gear ratio between the sleeve 81 and the shaft X is positive, which means that application of torque to the sleeve 81 in the direction of arrow |29, subjects the shaft X to torque in the same direction, and as a further consequence the shaft W becomes subjected to torque in the opposite direction of arrow |29. The gearing within the drum 21 is fully symmetrical, and it is therefore apparent that the gear ratio between the sleeve 12 and the shaft W is also positive. Consequently, the shaft W becomes subjected to torque in the same direction as that of arrow |29, and the shaft X becomes subjected to torque in the opposite di.

rection of arrow |29 when driving torque is applied to the sun gear 1| in the direction of arrow |29.

The result obtained by engagement of the clutch |58 in Fig. 9 is the same as that which is obtained by engagement of the clutch |06 in Fig. 1, and the result obtained by engagement of the clutch |59 in Fig. 9 is the same as that which is obtained by engagement of the clutch |08 in Fig. 1.

The drum 21 in Fig. 9 carries a bevel ring gear |44 which meshes with a bevel pinion I 43 for f transmitting main driving power to the drum 21 and differential gearing 38, 39 and 42.

Considering the mechanism shown in Figs, 1 to 5, and the various modifications thereof shown in Figs. 6 to 9, from a general point of view, the following should be noted. In each case the mechanism comprises: rst rotatably and orbitally movable pinion means which are' represented in Figs. 2 and 6 to 9 by the conical planet pinions 42; rotatable gearing which in the illustrated embodiments of the invention comprises the sun gear 39, and which is operatively connected with the rst pinion means 42 for epicyclic movement of the latter relative thereto; second rotatably and orbitally movable pinion means as represented by the planet pinions 16; pivotal supporting means, as represented by the pinion shafts 64, which are operatively connected, independently of the second pinion means 16, with the mentioned gearing (39) for rotation thereby about the axis of orbital movement of the second pinion means 16; a pair of relatively rotatable driven elements W and X which are differentially connected with each' other by said rst pinion means 42; driving means, which in Fig. 1 include the output shaft I2 and in Figs. 6 to 9 include the bevel gear |44, and which are operable to apply an orbital torque component to the first pinion means 42; other driving means which include the sun gear 86 and which are operable to apply a first torque component to ments of the invention, being an orbital torque component.

In the illustrated embodiments of the invention, the mentioned torque transmitting means include the sun gear 1|, the planet pinions 68 and the sleeve gear 80, all of which elements are effective. as explained in connection with Fig. 2, to subject the planet pinions 16, that is second pinion means, to an orbital torque component, in response to application of said rst (rotary) torque component to the second pinion means 16, so that said second pinion means will be driven rotativelv andv orbitallv, and said driven elements W and X will be rotated differentially relative to each other, upon application of said first (rotary) torque component to said second pinion means 16. The sleeve gear 86 in Figs. 2, 6, and 7, and either one of the gears |5| in Fig. 8, constitute a rotary torque transmitting element of the mentioned torque transmitting means, which is operatively connected with the second pinion means 16.

As explained hereinbefore, in connection with Fig. 2, the planet pinions 16, as well as the planet pinions 68, become subjected to orbital torque -when the sun gear 86 is rotated while the sun gear 1| is locked against rotation, and this function occurs likewise in all of the modified mechanisms. That is, each illustrated embodiment of the invention includes second pinion means 16 and third pinion means 68; driving means operable to apply a first torque component to the second pinions, as pointed out hereinbefore; a rotary torque transmitting element. such as the sleeve gear 86 or one of the gears |5| in Fig. 8, operatively connected with the second and third pinion means 16 and 68, and operative, upon application of said first torque component to said second pinion means 16, to apply a first torque component to said third pinion means 68; and torque transmitting means, which in the illustrated embodiments include the mentioned torque transmitting element (80 or |5|) and the sun gear 1 and which are operative to apply second torque components to said second and third pinion means in response to application of said rst torque component to said second pinion means 16.

It will further be noted thatV in each of the illustrated embodiments the over-all ratio of the gear train comprising the sun gear 86, planet pinions 16 and the gear section (84 in Fig. 2- and |5| in Fig. 6) in mesh with said planet pinions, is equal to the over-all ratio of the gear train comprising the sun gear 1|, the planet pinions 68 and the gear section (83 in Fig. 2 and |49 in Fig. 6) in mesh with the planet pinions 68.

Referring to Fig. 2, the drum 21 encloses a rst and a second epicyclic gearing each comprising three relatively rotatable elements, one

` element of the iirst epicyclic gearing being the right disk 46 which in effect forms the spider of said iirst gearing, another element of the rst epicyclic gearing being represented by the counter gear 18, and the last element of the iirst epicyclic gearing being represented by the auxiliary sun gear 86. Similarly, one element of the second epicyclic gearing is the left disk 46 which in effect forms the spider of the second epicyclic gearing, another element of the second gearing is represented by the counter gear 11, and the last element of the second epicyclic gearing is represented by the sun gear 1|. With these deflnitions, the mechanism shown in Fig. 2 may be considered as comprising means connecting a iirst of said elements of the lrst epicyclic gearing, for instance the right spider 46, independ ently of the second (18) and third (86) elements of said first gearing and independently of said second gearing (46, 11, 1 I) and of the main planet pinions 42, in power transmitting relation with one of the shafts W, X; means connecting a first of the elements of said second gearing, for instance the left spider 46, independently of the second (11) and third (1|) elements of said second gearing and independently of said first gearing (46, 18, 86) and of the main planet pinions 42, in power transmitting relation with the other of the shafts W, X; and rotatable torque transmitting means, as represented for instance by the bolts 19, in rotatively loose relation to the main planet carrier 4| and operatively connecting said second element (18) of said rst gearing Ywith said second element (11) of said second planet carrier 4|; auxiliary driving means, suchk as the reversible gearing at the right of Fig. l, i

are connected in driving relation with the third element (86) oi' one of the epicyclic gearings; and means, as represented in Fig. 1, for instance, by the bolts 13, are provided to restrain rotation of the third element (1|) of the other of the epicyclic gearings.

From the description hereinbefore of the mechanism shown in Fig. 2 it will further be apparent that the gear ratio between the rst (46) and the second (18) elements of the ilrst epicyclic gearing, at zero speed of its third element (86), is equal to the gear ratio between said iirst (46) and second (11) elements of the second epicyclic gearing at zero speed of the third element (1|) of said second gearing; and that the gear ratio between said first (46) and third (86) elements of said iirst gearing at zero speed of its second element (18), is substantially equal to the gear ratio between said rst (46) and third (1|) elements of said second gearing at zero speed of the second element (11) of said second gearing.

In the embodiment of the invention as shown in Fig. 9, the shaft 99 represents an auxiliary rotatable drive element; clutches |58 and |56 represent rst control means which are operable to selectively connect one or the other of the auxiliary sun gears 86 and 1| in driven relation with the auxiliary drive element 99; and the brakes |6| and |62 represent second control means which are operable to selectively restrain rotation of one or the other of the auxiliary sun gears 1|, 86. Y

More speciiically, the first control means, that is the clutches |58 and |59, are selectively operable by means of the cam cylinders |12, |13 and rockers |64, |68 to establish a driving connection between the auxiliary drive element 99 and the first auxiliary sun gear 86, or between the auxiliary drive element 99 and the second auxiliary between said auxiliary drive element and both of said auxiliary sun gears; and the second control means, namely the brakes IBI and |62, are selectively operable by means of the disks |14, I'IB and push rodsv |11, |18 to restrain rotation of the first auxiliary sun gear 86 while the first control means |58, |59 are operative to connect the second auxiliary sun gear 1| in driven relation with the auxiliary drive element 99, or to restrain rotation of the second auxiliary sun gear H while the first control means |58, |59 are operative to connect the first auxiliary sun gear 8B in driven relation with the auxiliary drive element 99. In the embodiment of the invention as shown in Fig. 9, the rst and second control means are so interrelated that the second control means will restrain rotation of both auxiliary sun gears while the first control means are operative to establish said non-driving relation between the auxiliary drive element 99 and the auxiliary sun gears 86 and 1|.

It should be understood that it is not intended to limit the invention to the particular forms and details described hereinabove and that the invention includes such other forms and modifications as are embraced by the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. A power transmitting mechanism comprising, first rotatably and orbitally movable pinion means, rotatable gearing operatively connected with said first pinion means for epicyclic movement of the latter relative thereto, second rotatably and orbitally movable pinion means, pivotal supporting means for said second pinion means operatively connected independently of the latter with said gearing for rotation thereby about the axis of orbital movement of said second pinion means; a pair of relatively rotatable driven elements differentially connected with each other by said rst pinion means, driving means operable to apply an orbital torque component to said first pinion means, other driving means operable to apply a first torque component to said second pinion means, and torque transmitting means operative to apply a second torque component to said second pinion means in response to application of said first torque component to the latter, so that said second pinion means will be driven rotatively and orbitally, and said driven elements will be rotated differentially relative to each other, upon application of said first torque component to said second pinion means.

2. A power transmitting mechanism as set forth in claim l, in which said torque transmitting means include a rotary torque transmitting element operatively connected with said second pinion means.

3. A power' transmitting mechanism as set forth in claim 1, in which said torque transmitting means include a rotary torque transmitting element mounted for rotation relative to said second pinion means about the axis of orbital rotation of the latter, and in which said rotary torque transmitting element has an annular gear section in mesh with said second pinion means.

4. A power transmitting mechanism as set forth in claim 1, in which said torque transmitting means include a rotary sleeve element mounted for rotation relative to said second pinion means about the axis of orbital rotation of the latter, and in which said sleeve element has an internal annular gear section in mesh with said second pinion means.

5. A power transmitting mechanism comprising, first pinion means mounted for rotary movement and for orbital movement conjointly with said rotary movement, rotatable gearing operatively connected with said rst pinion means for epicyclic movement of the latter relative thereto, second rotatably and orbitally movable pinion means, pivotal supporting means for said second pinion means extending axially in parallel radially spaced relation to the axis of orbital movement of said first pinion means and operatively connected, independently of said second pinion means, with said gearing for rotation thereby about said axis, a pair of relatively rotatable driven elements aligned on said axis and dierentially connected with each other by said first pinion means, driving means operable to apply an orbital torque component to said first pinion means, other driving means operable to apply a first torque component to said second pinion means, a sleeve gear concentric with said axis and in mesh with said second pinion means, and torque transmitting means including said sleeve gear, operative to apply a second torque component to said second pinion means in response to application of said first torque component to the latter, so that said second pinion means will be driven rotatively and orbitally, and said driven elements will be rotated differentially relative to each other, upon application of said first torque component to said second pinion means.

6. A power transmitting mechanism comprising first rotatably and orbitally movable pinion means, two relatively rotatable gear elements operatively connected with said rst pinion means for epicyclic movement of the latter relative thereto, second and third rotatably and orbitally movable pinion means, pivotal supporting means for said second pinion means operatively connected, independently of said second pinion means. with one of said gear elements for rotation thereby about the axis of orbital movement of said second pinion means, pivotal supporting means for said third pinion means operatively connected, independently of said third pinion means, with the other of said gear elements for rotation thereby about the axis of orbital movement of said third pinion means, a pair of relatively rotatable driven elements differentially connected with each other by said first pinion means, driving means operable to apply an orbital torque component to said rst pinion means, other driving means operable to apply a irst torque component to said second pinion means, a rotary torque transmitting element operatively connected with said second and third pinion means and operative, upon application of said first torque component to said second pinion means, to apply a iirst torque component to said third pinion means, and torque transmitting means, including said rotary torque transmitting element, operative to apply second Atorque components to said second and third pinion means in response to application of said first torque component to said second pinion means, so that said second and third pinion means will be driven rotatively and orbitally, and said driven elements will be rotated differentially relative to each other upon application of said first torque component to said second pinion means.

7. A power transmitting mechanism comprising first rotatably and orbitally movable pinion means, a pair of relatively rotatable driven elements differentially connected with each other by said first pinion means, second and third rotatably and orbitally movable pinion means, relatively rotatable supports connected in torque transmitting relation with said driven elements, respectively, one of said supports operatively mounting said second pinion means, and the other of said supports operatively mounting said third pinion means, driving means operable to apply an orbital torque component to said ilrst pinion means, a pairv of sun gears in mesh, respectively, with said second and third pinion means, means mounting one of said sun gears in rotatable relation to the other, means for restraining said other sun gear against rotation, a rotatable torque transmitting element operatively connected with both of said second and third pinion means, and auxiliary drive means operatively connected with said one sun gear.

8. A power transmitting mechanism comprising, first rotatably and orbitally movable pinion means, a pair of relatively rotatable driven elements differentially connected with each other by said first pinion means, second pinion means mounted on one oi' said driven elements for rotation relative thereto and for orbital movement thereby about the axis of orbital movement oi said ilrst pinion means, driving means operable to apply an orbital torque component to said rst pinion means, other driving means operable to apply a rotary torque component to said second pinion means, and torque transmitting means operative to apply an orbital torque component to said second pinion means in response to application of said rotary torque component to the latter, so that said second pinion means will be driven rotatively and orbitally, and said driven elements will be rotated diilerentially relative to each other upon application of said rotary torque component to said second pinion means.

9. A power transmitting mechanism comprising, first pinion means mounted for rotary movement and for orbital movement about a main movement, a pair of relatively rotatable driven elements aligned on said main axis and diierentially connected with each other by said ilrst pinion means, second pinion means rotatably mounted on one of said driven elements in radially spaced parallel relation to said main axis at right angles to the axis of said rotary ponent to said second pinion means in response v to application of said rotary torque component to the latter, so that said second pinion means will be driven rotatively and orbitally, and said driven elements will be rotated differentially relanaled, respectively, on said sun gears, iirst and second auxiliary sun gears aligned on said axis in rotatively loose relation to said planet carrier and shaft elements and in mesh, respectively, with said iirst and second auxiliary planet pinion means, means mounting one of said auxiliary sun gears in rotatable relation to the other, means for restraining said other auxiliary sun gear against rotation, auxiliary driving means for rotating said one auxiliary sun gear, and a sleeve gear inside of said annular planet carrier mounted coaxially with said shaft elements for rotation relative thereto and relative to said annular planet carrier and having tlrst and second gear sections in mesh, respectively, with said first and second auxiliary pinion means.

1l. A mechanism for driving a pair of relatively rotatable shaft elements, comprising a diierential mechanism operatively interposed between said shaft elements, a rotatable main driveelement connected in driving relation with the spider element of said diil'erential mechanism, flrst and second auxiliary sun gears each mounted for rotation relative to the other in rotatively loose relation to said spider and shaft elements, rst and second planetary pinion means in cooperative engagement, respectively, with said first and second sun gears and connected, respectively, with said shaft elements lor vorbital movement by the latter about said ilrst and second sun gears, 'a rotatable torque transmitting element mounted in rotatively loose relation to said spider element, shaft elements and auxiliary sun gears and operatively connected with both'f of said planetary pinion means, an auxiliary rotatable drive element, first control means operable to selectively connect one or the other of said auxiliary sun gears in driven relation with said auxiliary drive element, and second control means operable to selectively restrain rotation of one or the other of said auxiliary sun gears.

l2. A mechanism as set iorth in claim 11, in which said ilrst control means are selectively operable to establish a driving connection be` tween said auxiliary drive element and said ilrst auxiliary sun gear, or between said auxiliary drive element and said second auxiliary sun gear, or to establish a non-driving relation between said auxiliary drive element and both of said auxiliary sun gears, and in which said second control means are selectively operable to restrain rotation of said iirst auxiliary sun gear while said first control means are operative to connect said second auxiliary sun gear in driven relation with said auxiliary drive element, or to restrain rotation of said second auxiliary sun gear while said first control means are operative to connect said ilrst auxiliary sun gear in driven relation with said auxiliary drive element.

13. A mechanism as set forth in claim l1, in which said first control means are selectively operable to establish a driving connection between said auxiliary drive element and said first auxiliary sun gear, or between said auxiliary drive element and said second auxiliary sun gear, or to establish a non-driving relation between said auxiliary drive element and both of said auxiliary sun gears, in which said second control means are selectively operable to restrain rotation of one or the other or both of said auxiliary sun gears, and in which said flrst and second control means are so interrelated that said second control means will restrain rotation of both of said auxiliary sun gears while said rst control means are operative to establish said non-drivingr 25 relation between said auxiliary drive element and said auxiliary sun gears.

14. A steering differential for motor vehicles comprising, in combination, a pair of diilerentially interconnected shafts, a rotatable auxiliary sun gear, another auxiliary sun gear, torque with said first and second planetary pinion means and connected in torque transmitting relation with each other.

15. A steering differential for motor vehicles comprising, in combination, a `rotary cage structure, a pair of main sun gears and main planet pinions in mesh with said sun gears, rotatably mounted on said cage structure, a pair ,of auxiliary sun gears mounted coaxially with said cage structure for rotation of the latter and of said main sun gears relative thereto, first aux iliary planet pinions mounted on one of said main sun gears and meshing with one of said auxiliary sun gears, second auxiliary planet pinions mounted on the other of said main sun gears and meshing with the other of said auxiliargl sun gears, and an annular gear element mounted coaxially with said cage structure for rotation of the latter and of said main sun gears relative thereto and in rotatable relation to said auxiliary sun gears, said annular gear element having two circumferential series of teeth in mesh, respectively, with said first and second auxiliary planet pinions.

16. A steering differential for motor vehicles comprising, in combination, a rotary cage structure having axially opposite head sections, a pair of axially spaced main sun gears rotatable within said cage structure about the axis of the latter, main planet pinions mounted on said cage structure in cooperative engagement with said main sun gears, first auxiliary planet pinions mounted on one of said main sun gears for rota'- tion therewith within said cage structure about the axis of the latter, second auxiliary planet pinions mounted on the other of said main sun gears for rotation therewith within said cage structure about the axis of the latter, a pair of auxiliary sun gears in mesh, respectively, with said first and second auxiliary planet pinions, tubular supporting shafts for said auxiliary sun gears, respectively, one extending axially through one of said head sections and the other extending axially through the other of said head sections, an annular rotatable gear element within said cage structure having axially opposite gear sections in meshed relation, respectively, with said first and second auxiliary planet pinions, and a pair of driven shafts extending axially through said...

tubular shafts and nonrotatably connected, respectively, at their relatively adjacent ends with said main sun gears.

17. A steering differential as set forth in claim 16, in which said first auxiliary planet pinions are mounted on and located at the axially inner side of one of said main sun gears, in which saidI second auxiliary planet pinions are mounted on and located at the axially inner side of the other 26 of said main sun gears, and in which said tubular supporting shafts for said auxiliary sun gears extend through central apertures of said main sun gears, respectively.

18. A steering differential as set forth in claim 16, in which said cage structure comprises a drum section and a. pair of head sections detachably secured to said drum section at the axially opposite ends, respectively, of the latter; .in which an annular carrier for said main planet pinions comprises a ring section and trunnions extending radially outwardly from said ring sections; and in which cover plates mounting said trunnions are detachably secured to said drum section over circumferentially spaced apertures of the latter.

19. A steering differential as set forth in claim 16, in which each of said main sun gears comprises a disk section having a peripheral axially extending rim portion, and a ring gear section having an axial spline connection with said rim portion of said disk section.

20. A power steering mechanism for .'notor vehicles comprising, in combination, a pair of relatively rotatable shafts, main sun gears secured, respectively, to said shafts, a rotatable main planet carrier, main planet pinion means rotatably mounted on said main planet carrier and connecting said main sun gears in torque transmitting relation 'with each other; a spider, an auxiliary sun gear and a counter gear forming three relatively rotatable elements of a first epicyclic gearing and being operatively interconnected by planet pinion means on said spider; another spider, auxiliary sun gear and counter gear forming three relatively rotatable elements of a second epicyclic gearing and being operatively interconnected by planet pinion means on said other spider; means connecting a first of said elements of said first gearing, independently of the second and third elements of said first gearing and independently of said second gearing and of said main planet pinion means, in power transmitting relation with one of said shafts; means connecting a first of said elements of said second gearing, independently of the second and third elements of said secondgearing and independently of said first gearing and of said main planet pinion means, in power transmii-.ting relation with the other of said shafts; rotatable torque transmitting means in rotatively loosrelation to said main planet carrier and operatively connecting said second element of said rst gearing With said second element of said second gearing, independently of said first and third elements of each of said epicyclic gearings, main driving means connected in driving relation with said main planet carrier, auxiliary driving means connected in driving relation with the third element of one of said epicyclic gearings, and means for restraining rotation of the third element of the other of said epicyclic gearings.

21. A power steering mechanism as set forth in claim 20, in which the sun gear, counter gear and planet pinion means of said first epicyclic gearing are relatively proportioned, and the sun gear, counter gear and planet pinion means of sald second epicyclic gearing are relatively proportioned so that the gear ratio between said first and second elements of said first gearing, at zero speed of its third element, is substantially equal to the gear ratio between said first and second elements of said second gearing at zero speed of the third element of said second gearing.

22. A power steering mechanism as set forth in .claim 20, in which the sun gear, counter gear and planet pinion means of said first epicyclic gear train are relatively proportioned, and the sun gear, counter gear and planet pinion means of said second epicyclic gear train are relatively proportioned, so that the gear ratio between said rst and second elements of said first gearing, at zero speed of its third element, is substantially equal to the gear ratio between said xst and second elements of said second gearing at zero speed of the thirdelement of said second gearing, and so that the gear ratio between said rst and third elements of said i'lrst gearing. at zero speed of its second element, is substantially equal to the gear ratio between said first and third elements of said second gearing at zero speed of the second element of said second gearing.

23. A power steering mechanism for motor ve.- hicles comprising. in combination, a pair of relatively rotatable shafts, main sun gears secured, respectively, to said shafts, a rotatable4 main planet carrier, main planet pinion means rotatably mounted on said main planet carrier and connecting said main sun gears in torque transmitting relation with each other; a spider, an auxiliary sun gear and a counter gear forming three relatively rotatable elements of a iirst epicyclic gearing and being operatively interconnected by planet pinion means on said spider; another spider, auxiliary sun gear and counter gear forming three relatively rotatable elements of a second epicyclic gearing and being operatively interconnected by planet pinion means on said other spider; means connecting said spider of said iirst gearing independently of said sun and counter gears of said first gearing and independently of said second gearing and of said main planet pinion means, in power transmitting relation with one of said shafts; means connecting said spider of said second gearing, independo ently of said sun and counter gears of said second gearing and independently of said rst gearing and of said main planet pinion means in power transmitting relation with the other of said 5 shafts; rotatable torque transmitting means in rotatively loose relation to said main planet carrier and operatively connecting said counter gear of said first gearing with said counter gear of said second gearing, independently of said sun gear and spider of 'ach of said epicyclic gearings,

main driving means Vconnected in driving relation with said main planet carrier. auxiliary driving means connected in driving relation with said sun gear o f one of said epicyclic gear gearings, and means for restraining rotation of said sun gear of the other of said epicyclic gearings.

24. A power steering mechanism as set forth in claim 23, in which the sun gear of said first epicyclic gearing has a smaller pitch diameter than the counter gear of said first epicyclic gearing, and in which thesun gear of said second epicyclic gearing has a smallerpitch diameter than the counter gear of said second epicyclic gearing.

25. A power steering mechanism as set forth in claim 24, in which the pitch diameter of the sun gear of said rst epicyclic gearing is equal to the pitch diameter of said sun gear of said second epicyclic gearing, and in which the pitch diameter of the counter gear of said first epicyclic gearing is equal to the pitch diameter of the counter gear of said second epicyclic gearing.

EMIL F. NORELIUS.

REFERENCES CITED The following references are of recordvin the file of this patent:

UNITED STATES PATENTS 

